This circuit with TTL compatible output was found in a 1968 US documentation. The circuit is powered by 5 V and the frequency can be changed by changing the crystal.
This indicator with the integrated circuits CA3162E and 3161E was published in the July 1990 issue...
This variable high pass filter covers the range from 23 Hz to 700 Hz with the components used. The...
August 2017 - This new component of On Semiconductor is available from Mouser Electronics. This is an...